<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title></title>
	</head>
	<body>
		1.找父节点：parentNode
		2.找儿子： children
		3.找大哥：previousElementSibling
		4.找小弟：nextElementSibling
		
		
	</body>
</html>
